Mono cannot find dll that seems to exist - vb.net

Question

I have just upgraded my 64-bit ubuntu 14.04.2 LTS to the latest mono. I followed the instructions on this page a few months ago, and before today had been using mono 3 without issue. Today I upgraded, which moved me to mono 4.0.1:
$ mono --version
Mono JIT compiler version 4.0.1 (tarball Tue Apr 28 11:47:58 UTC 2015)
I have successfully compiled this program using monodevelop, but the exact same issue manifests with a VS2013-compiled binary [newlines exactly as they appear in the output]:
$ file RTAM_Basic_Pre.exe
RTAM_Basic_Pre.exe: PE32 executable (console) Intel 80386 Mono/.Net Assembly, for MS Windows
$ mono RTAM_Basic_Pre.exe
Unhandled Exception:
System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.VisualBasic, Version=11.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies.
File name: 'Microsoft.VisualBasic, Version=11.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'
[ERROR] FATAL UNHANDLED EXCEPTION: System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.VisualBasic, Version=11.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies.
File name: 'Microsoft.VisualBasic, Version=11.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'
Thing is, I'm really quite sure that file exists:
$ pwd
/usr/lib/mono/gac/Microsoft.VisualBasic/11.0.0.0__b03f5f7f11d50a3a
$ ls -l
-rw-r--r-- 1 root root 350720 Apr 27 12:00 Microsoft.VisualBasic.dll
$ file Microsoft.VisualBasic.dll
Microsoft.VisualBasic.dll: PE32 executable (DLL) (console) Intel 80386 Mono/.Net assembly, for MS Windows
It's possible that the error is the "... or one of its depedencies", but it's not clear to me how actually diagnose what's happening.

Answer 1

Through tracing a simple VB helloworld program with MONO_LOG_LEVEL=debug MONO_LOG_MASK=asm I found the following:
Mono: The request to load the assembly Microsoft.VisualBasic v11.0.0.0 was remapped to v10.0.0.0
Turns out the v11.0.0.0 version number is actually incorrect, this pull request should fix it: https://github.com/mono/mono-basic/pull/8

Answer 2

The first thing I would try in a situation like this is to see if the system can fix the dependencies itself. The first few steps on the installation guide should have set you up with the needed repositories. In the shell, try executing:
sudo apt-get install -f mono-complete
The '-f' flag should tell the system to make sure the dependencies are there.
I hope this can be of help! Apologies if that doesn't turn out to be the case. 030